39de5b7f82
Before of this patch, we looked at the unveil data of the FinalizerTask, which naturally doesn't have any unveil restrictions, therefore allowing an unveil bypass for a process that enabled performance coredumps. To ensure we always check the dumped process unveil data, an option to pass a Process& has been added to a couple of methods in the class of VirtualFileSystem.
128 lines
6.3 KiB
C++
128 lines
6.3 KiB
C++
/*
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* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/Badge.h>
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#include <AK/Error.h>
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#include <AK/Function.h>
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#include <AK/HashMap.h>
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#include <AK/NonnullOwnPtrVector.h>
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#include <AK/OwnPtr.h>
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#include <AK/RefPtr.h>
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#include <Kernel/FileSystem/FileBackedFileSystem.h>
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#include <Kernel/FileSystem/FileSystem.h>
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#include <Kernel/FileSystem/InodeIdentifier.h>
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#include <Kernel/FileSystem/InodeMetadata.h>
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#include <Kernel/FileSystem/Mount.h>
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#include <Kernel/FileSystem/UnveilNode.h>
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#include <Kernel/Forward.h>
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#include <Kernel/Library/LockRefPtr.h>
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#include <Kernel/Locking/SpinlockProtected.h>
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namespace Kernel {
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// Kernel internal options.
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#define O_NOFOLLOW_NOERROR (1 << 29)
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#define O_UNLINK_INTERNAL (1 << 30)
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struct UidAndGid {
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UserID uid;
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GroupID gid;
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};
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enum class AccessFlags {
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None = 0,
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EffectiveAccess = 1 << 0,
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DoNotFollowSymlinks = 1 << 1,
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};
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AK_ENUM_BITWISE_OPERATORS(AccessFlags);
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class VirtualFileSystem {
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public:
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// Required to be at least 8 by POSIX
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// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
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static constexpr int symlink_recursion_limit = 8;
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static void initialize();
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static VirtualFileSystem& the();
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VirtualFileSystem();
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~VirtualFileSystem();
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ErrorOr<void> mount_root(FileSystem&);
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ErrorOr<void> mount(FileSystem&, Custody& mount_point, int flags);
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ErrorOr<void> bind_mount(Custody& source, Custody& mount_point, int flags);
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ErrorOr<void> remount(Custody& mount_point, int new_flags);
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ErrorOr<void> unmount(Custody& mount_point);
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ErrorOr<NonnullLockRefPtr<OpenFileDescription>> open(Credentials const&, StringView path, int options, mode_t mode, Custody& base, Optional<UidAndGid> = {});
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ErrorOr<NonnullLockRefPtr<OpenFileDescription>> open(Process const&, Credentials const&, StringView path, int options, mode_t mode, Custody& base, Optional<UidAndGid> = {});
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ErrorOr<NonnullLockRefPtr<OpenFileDescription>> create(Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
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ErrorOr<NonnullLockRefPtr<OpenFileDescription>> create(Process const&, Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
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ErrorOr<void> mkdir(Credentials const&, StringView path, mode_t mode, Custody& base);
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ErrorOr<void> link(Credentials const&, StringView old_path, StringView new_path, Custody& base);
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ErrorOr<void> unlink(Credentials const&, StringView path, Custody& base);
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ErrorOr<void> symlink(Credentials const&, StringView target, StringView linkpath, Custody& base);
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ErrorOr<void> rmdir(Credentials const&, StringView path, Custody& base);
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ErrorOr<void> chmod(Credentials const&, StringView path, mode_t, Custody& base, int options = 0);
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ErrorOr<void> chmod(Credentials const&, Custody&, mode_t);
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ErrorOr<void> chown(Credentials const&, StringView path, UserID, GroupID, Custody& base, int options);
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ErrorOr<void> chown(Credentials const&, Custody&, UserID, GroupID);
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ErrorOr<void> access(Credentials const&, StringView path, int mode, Custody& base, AccessFlags);
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ErrorOr<InodeMetadata> lookup_metadata(Credentials const&, StringView path, Custody& base, int options = 0);
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ErrorOr<void> utime(Credentials const&, StringView path, Custody& base, time_t atime, time_t mtime);
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ErrorOr<void> utimensat(Credentials const&, StringView path, Custody& base, timespec const& atime, timespec const& mtime, int options = 0);
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ErrorOr<void> rename(Credentials const&, Custody& old_base, StringView oldpath, Custody& new_base, StringView newpath);
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ErrorOr<void> mknod(Credentials const&, StringView path, mode_t, dev_t, Custody& base);
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ErrorOr<NonnullRefPtr<Custody>> open_directory(Credentials const&, StringView path, Custody& base);
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ErrorOr<void> for_each_mount(Function<ErrorOr<void>(Mount const&)>) const;
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ErrorOr<NonnullLockRefPtr<FileBackedFileSystem>> find_already_existing_or_create_file_backed_file_system(OpenFileDescription& description, Function<ErrorOr<NonnullLockRefPtr<FileSystem>>(OpenFileDescription&)> callback);
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InodeIdentifier root_inode_id() const;
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void sync_filesystems();
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void lock_all_filesystems();
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static void sync();
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NonnullRefPtr<Custody> root_custody();
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ErrorOr<NonnullRefPtr<Custody>> resolve_path(Credentials const&, StringView path, NonnullRefPtr<Custody> base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
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ErrorOr<NonnullRefPtr<Custody>> resolve_path(Process const&, Credentials const&, StringView path, NonnullRefPtr<Custody> base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
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ErrorOr<NonnullRefPtr<Custody>> resolve_path_without_veil(Credentials const&, StringView path, NonnullRefPtr<Custody> base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
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private:
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friend class OpenFileDescription;
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UnveilNode const& find_matching_unveiled_path(Process const&, StringView path);
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ErrorOr<void> validate_path_against_process_veil(Process const&, StringView path, int options);
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ErrorOr<void> validate_path_against_process_veil(Process const& process, Custody const& custody, int options);
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ErrorOr<void> validate_path_against_process_veil(Custody const& path, int options);
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ErrorOr<void> validate_path_against_process_veil(StringView path, int options);
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bool is_vfs_root(InodeIdentifier) const;
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ErrorOr<void> traverse_directory_inode(Inode&, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>);
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bool mount_point_exists_at_inode(InodeIdentifier inode);
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// FIXME: These functions are totally unsafe as someone could unmount the returned Mount underneath us.
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Mount* find_mount_for_host(InodeIdentifier);
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Mount* find_mount_for_guest(InodeIdentifier);
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LockRefPtr<Inode> m_root_inode;
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SpinlockProtected<RefPtr<Custody>, LockRank::None> m_root_custody {};
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SpinlockProtected<IntrusiveList<&Mount::m_vfs_list_node>, LockRank::None> m_mounts {};
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SpinlockProtected<IntrusiveList<&FileBackedFileSystem::m_file_backed_file_system_node>, LockRank::None> m_file_backed_file_systems_list {};
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SpinlockProtected<IntrusiveList<&FileSystem::m_file_system_node>, LockRank::FileSystem> m_file_systems_list {};
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};
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}
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